The suspected hideout of Pakistani Taliban leader Baitullah Mehsud and Al-qaeda and that Americans and NATO forces could put matching pressure on militants from the Afghanistan side.

US on Saturday said Pakistan could be planning a separate military campaign in Waziristan, the suspected hideout of Pakistani Taliban leader Baitullah Mehsud and Al-qaeda and that Americans and NATO forces could put matching pressure on militants from the Afghanistan side.

Noting that Waziristan has a large concentration of terrorist elements, specially big chunk of Al-qaeda members, a top Pentagon official said "so an offensive, there not necessarily the sole instrument we need to defeat Al-qaeda, certainly can play and important role."

While acknowledging the Pakistani plan, the official said a central element of the new "US going forward strategy is to have pressure on both sides of the border", apparently indicating that when the Pakistan army pushes into Waziristan, US and NATO forces could apply pressure from the Afghan side.

As part of the element of the strategy to look at Afghanistan and Pakistan as an integrated theater of operation, is to have mutual reinforcing efforts, he said.

"The Border Coordination Centres provide some of that role, exchange of information, but also ongoing operations on both sides to do that," he said.

The top official said US and Pakistan forces had similar coordination during the Pak army operations in Bajaur last year and similar offensives on the Afghan sides in Kunar province.

"I think this is the model of operations in Waziristan as well as elsewhere along the long Pak-Afghan border," the top official said.

Stating that Baitullah Mehsud is the "public enemy number one" in Pakistan right now, the Pentagon official said Islamabad would launch another operation in his stronghold of South Waziristan once the Swat operation is over.

The Pentagon official's broad hints that Waziristan operations could be in the offing came as a State Department official said Washington was not aware of any moves by Pakistan to impose martial law in the country's troubled north west region.

While saying Pakistan was going through an "extraordinary situation", Assistant Secretary of State for Public Affairs PJ Crowley told reporters that there was an aggressive military action occurring in Pakistan to deal with these issues.

When asked about news reports that Pakistan government may impose martial law in parts of the country, Crowley said he was not aware.

"How the Pakistani military decides to engage in this fight is really a matter for the them and the government. We are working aggressively to support Pakistan in this effort," he said.